So, let's say you have an mbox full of mail and you want to get all the To: addresses out of it. And let's say you've seen a bunch of intimidating complicated examples like http://stackoverflow.com/questions/7166922/extracting-the-body-of-an-email-from-mbox-file-decoding-it-to-plain-text-regard or http://nbviewer.ipython.org/github/furukama/Mini…

mbox-unique-email-addresses.py

# via http://stackoverflow.com/questions/14903664/determine-unique-from-email-addresses-in-maildir-folder

import mailbox
import email

mbox = mailbox.mbox('DADEOL/AOL Mail sorted/Saved.DADEOL Sent.mbox')

uniq_emails = set(email.utils.parseaddr(msg['to'])[1].lower() for msg in mbox)

for a in uniq_emails:
    print a

print len(uniq_emails)

@theojepsen glad it was useful! Thanks for providing an additional one.